Cutter for drill pipe protectors



INVENTOR.

CLYDE R. SIMPSON ATTORNEYS.

Aug. 21, 1951 C. R. SIMPSON CUTTER FOR DRILL PIPE PROTECTORS Filed March 21, 1949 Patented Aug. 21, 1951 UNITED STATES PATENT OFFICE to Thomas P. Pike Drilling Co., Los Angeles, Calif., a corporation of California.

This invention relates to rotary well drilling equipment and is particularly directed to a device for reducing the outside diameter oi drill pipe protectors while they are in position on the plpe.

In the art of well drilling by the rotary process, annular rubber protectors are often mounted on the drill pipe and held in position by the resilience of the rubber material. These rubber protectors act as wear-receiving elements while the drill pipe is turning within casing previously mounted in the well bore. The protectors which f7 Claims.

are initially installed on the drill pipe are of a size corresponding to the inside diameter of the casing in which the drill pipe is to be run.

Application March 21, 1949, Serial No. 82,567

Should it be desired to use the drill pipe later in another well having smaller casing, it has been necessary heretofore to remove the protectors and install new ones of smaller outside diameter. This entails waste of material and involves conn sderable time for applying the new protectors to the pipe.

In accordance with my invention, I provide apparatus for trimming the outside diameter of rubber drill pipe protectors so that they may operate in smaller casing. Accordingly, it is the principal object of my invention to provide a simple and rugged device which may be used within the well drilling derrick for quickly reducing the outside diameter of rubber protectors While they are in position on the pipe.

Another object is to provide a device of this type which may be employed during the normal operation of lowering the drill pipe into the hole.

Another object is to provide a device of this type having an integral shell or body provided at one end with a circular knife edge and adapted to receive segmental bushings at the other end for maintaining the shell or body in coaxial position with respect to the pipe.

Other and more detailed objects and advantages will appear hereinafter.

In the drawings:

Figure l is a sectional elevation showing a preierred embodiment of my invention,

Figure 2 is a side elevation partly broken away.

Figure 3 is a perspective View of one of the segmental bushing elements.

Referring to the drawings, the drill pipe Ill is provided with one or more encircling rubber protector collars II held in place by the resilience of the rubber material. The drill pipe is provided with the usual tool joints I2 which are of larger diameter than the pipe and are used for threadedly connecting adjacent pipe sections.

In accordance with my invention, I provide a cylindrical shell or body I3 tapering at its upper end to a circular knife edge Ill. The body i3 is provided with an axial opening I5. The portion of the opening adjacent the cutting edge Iii is reduced in diameter as shown at I6. The bore I5 is sufficiently large to pass the -tool joint l2.

A pair of segmental bushings Il and I8 are insertable into the lower end of the body i3 and into the opening I5. These bushing segments t closely within the opening I5 and have running clearance with the outside diameter of the pipe I0 so that the body I3 and cutting knife I4 are maintained in a coaxial position with respect to the pipe lil. Each of the bushings Il and IS is provided with a laterally projecting ear i9. ri'lie ear I9 may be attached to the bushing in any convenient fashion such as, for example, by welding. The ears I9 extend outwardly beyond the outer diameter oi the body I3 and may be looped as shown at Z. Each of the bushing segments may include a segmental annular portion 2i naving a ange 22 adjacent the ear 23. The flange 22 is adapted to engage the lower end oi the body I3. The ears I9 act as pendent support elements for supporting the entire assembly from a pair of tension lines 23.

Means are provided for preventing rotation of the bushing segments Il and I8 with respect to the body I3 when the pipe l0 is rotated. As shown in the drawings, this means includes a key 24 on the bushing segment Il which is received within a slot 25 provided on the lower end of the body I3. Since the bushing segments completely encircle the pipe l, locking one of them with respect to the body i3 serves to lock the other.

Horizontally extending torque-resisting handles 26 are provided on the body for preventing rotation of the body when the knife I4 engages the rotating collar l l.

In operation the device is suspended on the pendent lines 23 which in turn may be connected to the usual cat line (not shown) employed in connection with the drilling rig. The drill pipe is handled in the conventional fashion and is connected section by' section or stand by stand by threading together complementary halves of the tool joints. A section or stand is hoisted in the usual Way by means of an elevator (not shown) and then the cutter device embodying my invention is swung under the lower end of 'the pipe while thus suspended in the elevator. The handles 26 are gripped manually to move the cutter device over the tool joint on the lower end of the suspended pipe section or stand. When the body I3 has been raised above the position of the tool joint the segmental bushings Il and I8 are installed in the lower end of the opening I5, and the weight of the assembly is supported by means of the pendent lines 23. The pipe section is then threadedly connected to the next lower section in a conventional manner. The rotary table (not shown) employed in connection with conventional rotary drilling rigs is then turned to cause the newly added pipe section to rotate. While the pipe is rotating the cat line (not shown) is tensioned to lift the cutter assembly upwardly along the pipe Iel to bring the circular knife i-l into engagement with the oversize rubber protector li. The sharpened edge le is held concentric with the pipe by reason of the running nt between the bushing segments il and I8 and the outer diameter of the pipe It. The cutter assembly is moved upwardly the pipe and bushing rotate, thereby trimming off a section of the outer diameter of the rubber protector i l. The portion trimmed on" remains on the outside of the upper tapered portion of the body i3 while the collar as trimmed passes into the bore i6. When the cutting operation has been completed the outer ring encircling the upper portion of the body is out away and the body i3 is moved upwardly to position the protector ring as trimmed within the opening I5 which is somewhat larger in diameter than the bore ie. The body i3 is then supported by means of the handle 2li while the segmental bushings il and i8 are removed to permit the pipe le and reduced collar lI to move downwardly through the opening i5. The segmental bushings Il and l are reinserted for trimming any additional protector collars on that particular stand of drill pipe. When the upper end of the pipe is lowered to a position near the rotary machine (not shown), the usual slips are inserted in the rotary machine to support the pipe and the elevator is disconnected. The body I3 may then be passed upwardly over the tool joint on the upper end of the pipe.

If additional sections or stands are to be added the body I3 may be allowed to rest on the rotary table encircling the pipe section which is held by the slips. After the new section of pipe has been threadedly connected the body is moved upwardly' over the connected tool joints. The segmental bushings are then reinserted and the cutting operations on the rubber protector col.- lars proceed in the mannerk described above.

It will be understood from this description that the protector collars II may be trimmed to the desired outside diameter during the normal operation of lowering the drill pipe into the hole. Very little additional time is required over that consumed in the normal operation of going into the hole.

Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

I claim:

1. A cutter assembly for reducing the outside diameter of protectors encircling a pipe, comprising the combination of a body having a central opening extending therethrough through which the pipe may pass, said central opening being large enough to pass a tool joint, one end of the body being provided with a knife, and a plurality of bushing segments insertable into the other end of the opening around the pipe to maintain the body and knife concentric with respect to the pipe.

2. A cutter assembly for reducing the outside diameter of protectors encircling a pipe, comprising the combination of a body having a central opening extending therethrough through Which the pipe may pass, said central opening being large enough to pass a tool joint, one end of the body being provided with a circular knife, a pair of semi-circular bushing segments insertable into the other end of the opening around the pipe to maintain the body and knife concentric with respect to the pipe, and pendent support elements on each of the bushing segments extending laterally beyond the body.

3. A cutter assembly for reducing the outside diameter of protectors encircling a pipe, comprising the combination of a body having a central opening extending therethrough through which the pipe may pass, one end of the body being tapered to form a circular knife, a bushing insertable into the other end of the opening around the pipe to maintain the body and knife concentric with respect to the pipe, said bushing being split on axially extending lines into a plurality of segments, whereby the bushing may be applied laterally to the pipe, means for preventing relative rotary movement between the bushing segments and the body, and pendent support elements on certain of the bushing segments extending laterally beyond the body.

4. A cutter assembly for reducing the outside diameter of protectors encircling a pipe, comprising the combination of a body having a central opening extending therethrough through which the pipe may pass, said central opening being large enough to pass a tool joint, one end of the body being tapered to form a circular knife, the portion of the body opening adjacent the knife being cylindrical and of reduced d zetel', a pair or" bushing segments insertable into the other end of the opening around the pipe to maintain the body and knife concentric with respect to the pipe, key means for preventing relative rotary movement between one of the bushing segments and the body, and a pendent support element on each of the bushings.

5. A cutter assembly for reducing the outside diameter of rubber protector collars encircling a pipe, comprising the combination of a body having a central opening extending therethrough through which the pipe may pass, one end of the bodybeing tapered to form a continuous circular knife, the portion of the body opening adjacent the knife being cylindrical and of reduced diameter, a bushing insertable into the other end of the opening around the pipe to maintain the body and knife concentric with respect to the pipe, said bushing being split on axially extending lines into a plurality of segments, whereby the bushing may be applied laterally to the pipe, a key for preventing relative rotary movement between one of the bushing segments and the body, and pendent support elements on certain of the bushing segments extending laterally beyond the body.

6. A cutter assembly for reducing the outside diameter of rubber protector collars mounted upon a rotating drill pipe, comprising in combination: a body having a central opening large enough to pass a tool joint, one end of the body having a knife for cutting the rubber protector collars, a plurality of bushing segments insertable laterally around the pipe and into the other end of the central opening to maintain the body and knife concentric with respect to the rotating pipe, and pendent support elements on the bushing segments.

7. A cutter assembly for reducing the outside diameter of rubber protector collars mounted upon a rotating drill pipe, comprising in combination: a body having a central opening large enough to pass a tool joint, one end of the body having a knife for cutting the rubber protector collars, a plurality of bushing segments insertable into the other end of the central opening around the pipe to maintain the body and knife concentric with respect to the rotating pipe. each of the bushing segments having a flange adapted to engage the end of the body, and pendent support elements on the bushing segments.

CLYDE R. SMPSON.

REFERENCES CTED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 1,270,038 Malm et al July 18, 1918 1,420,847 Konigsberg June 27, 1922 

